Datasheet

ManualsBrandsANALOG DEVICES ManualsLinear ICsLinear IC - Op-amp Multi-purpose SOIC 8

36 V Precision, 2.8 nV/√Hz

Rail-to-Rail Output Op Amp

Data Sheet

AD8675

Rev. E

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registered trademarks are the property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

www.analog.com

FEATURES

Very low voltage noise: 2.8 nV/√Hz

Rail-to-rail output swing

Low input bias current: 2 nA maximum

Very low offset voltage: 75 µV maximum

Low input offset drift: 0.6 µV/°C maximum

Very high gain: 120 dB

Wide bandwidth: 10 MHz typical

±5 V to ±18 V operation

APPLICATIONS

Precision instrumentation

PLL filters

Laser diode control loops

Strain gage amplifiers

Medical instrumentation

Thermocouple amplifiers

PIN CONFIGURATIONS

NULL

–IN

+IN

V–

NULL

V+

OUT

NC = NO CONNECT

AD8675

TOP VIEW

(Not to Scale)

05564-001

Figure 1. 8-Lead SOIC_N (R-8)

NULL

–IN

+IN

V–

NULL

V+

OUT

NC = NO CONNECT

AD8675

TOP VIEW

(Not to Scale)

05564-002

Figure 2. 8-Lead MSOP (RM-8)

GENERAL DESCRIPTION

The AD8675 precision operational amplifier has ultralow offset,

drift, and voltage noise combined with very low input bias currents

over the full operating temperature range. The AD8675 is a

precision, wide bandwidth op amp featuring rail-to-rail output

swings and very low noise. Operation is fully specified from

±5 V to ±15 V.

The AD8675 features a rail-to-rail output like that of the OP184,

but with wide bandwidth and even lower voltage noise, combined

with the precision and low power consumption like that of the

industry-standard OP07 amplifier. Unlike other low noise, rail-

to-rail op amps, the AD8675 has very low input bias current

and low input current noise.

With typical offset voltage of only 10 µV, offset drift of 0.2 µV/°C,

and noise of only 0.10 μV p-p (0.1 Hz to 10 Hz), the AD8675 is

perfectly suited for applications where large error sources cannot

be tolerated. For applications with even lower offset tolerances,

the proprietary nulling capability allows a combination of both

device and system offset errors up to 3.5 mV (referred to the

input) to be compensated externally. Unlike previous circuits,

the AD8675 accommodates this adjustment without adversely

affecting the offset drift, CMRR, and PSRR of the amplifier.

Precision instrumentation, PLL, and other precision filter circuits,

position and pressure sensors, medical instrumentation, and

strain gage amplifiers benefit greatly from the very low noise,

low input bias current, and wide bandwidth. Many systems can

take advantage of the low noise, dc precision, and rail-to-rail

output swing provided by the AD8675 to maximize SNR and

dynamic range.

The smaller packages and low power consumption afforded by

the AD8675 allow maximum channel density or minimum

board size for space-critical equipment.

The AD8675 is specified for the extended industrial temperature

range (−40°C to +125°C). The AD8675 amplifier is available in

the tiny 8-lead MSOP, and the popular 8-lead, narrow SOIC,

RoHS compliant packages. MSOP packaged devices are only

available in tape and reel format.

For the dual version of this ultraprecision, rail-to-rail op amp,

see the AD8676 data sheet.

The AD8675 and AD8676 are members of a growing series of

low noise op amps offered by Analog Devices, Inc.

Table 1. Voltage Noise

Package 0.9 nV 1.1 nV 1.8 nV 2.8 nV 3.8 nV

Single AD797 AD8597 ADA4004-1 AD8675 AD8671

Dual AD8599 ADA4004-2 AD8676 AD8672

Quad ADA4004-4 AD8674

Summary of content (12 pages)

PAGE 1
PIN CONFIGURATIONS Very low voltage noise: 2.8 nV/√Hz Rail-to-rail output swing Low input bias current: 2 nA maximum Very low offset voltage: 75 µV maximum Low input offset drift: 0.6 µV/°C maximum Very high gain: 120 dB Wide bandwidth: 10 MHz typical ±5 V to ±18 V operation NULL 1 –IN 2 +IN 3 V– 4 AD8675 8 NULL 7 V+ 6 OUT TOP VIEW (Not to Scale) 5 NC 05564-001 FEATURES NC = NO CONNECT Figure 1.
PAGE 2
AD8675 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Thermal Resistance .......................................................................5 Applications ....................................................................................... 1 Power Sequencing .........................................................................5 Pin Configurations ..........................................................
PAGE 3
Data Sheet AD8675 SPECIFICATIONS ELECTRICAL SPECIFICATIONS VS = ±5.0 V, VCM = 0 V, VO = 0 V, TA = +25°C, unless otherwise specified. Table 2.
PAGE 4
AD8675 Data Sheet VS = ±15 V, VCM = 0 V, VO = 0 V, TA = +25°C, unless otherwise specified. Table 3.
PAGE 5
Data Sheet AD8675 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 4.
PAGE 6
AD8675 Data Sheet TYPICAL PERFORMANCE CHARACTERISTICS ±15 V and ±5 V, TA = 25°C, unless otherwise specified. 10 150 VS = ±15V VOLTAGE NOISE DENSITY (nV/ Hz) 9 100 8 7 50 VOS (µV) 6 5 4 TYPICAL 0 –50 3 –100 2 1 10 100 1k 10k 100k FREQUENCY (Hz) 05564-011 –150 –40 0 0 20 40 60 80 100 120 TEMPERATURE (°C) Figure 6. Offset Voltage vs. Temperature Figure 3. Voltage Noise Density vs.
PAGE 7
Data Sheet AD8675 120 100 4 180 RL = 2kΩ CL = 35pF θM = 55.2 GAIN 80 3 2 40 0 60 0 0 –20 VS = ±15V –1 PHASE 20 GAIN (dB) VS = ±5V 1 IB (nA) 120 60 –60 –40 –60 –2 –120 –80 –3 PHASE MARGIN (Degrees) 5 –120 100 –20 0 20 40 60 80 100 10k 120 TEMPERATURE (°C) 100k 1M 10M –180 100M FREQUENCY (Hz) 05564-007 –5 –40 1k Figure 9. Input Bias Current vs. Temperature 05564-018 –100 –4 Figure 12. Gain and Phase vs. Frequency 60 2.4 50 40 CLOSED-LOOP GAIN (dB) 1.
PAGE 8
AD8675 Data Sheet 0.1 VIN = ±10V RL = 2kΩ AV = +1 0 –5 40 –0.1 30 –0.2 20 –0.3 10 0 –0.4 VOUT –0.5 –10 –10 VIN = 200mV p-p AVO = –100 RL = 10kΩ –0.6 –0.7 –4 05564-020 –15 TIME (10µs/DIV) 1 11 16 21 26 31 –30 36 Figure 18. Positive Overvoltage Recovery 4 50 VIN = 200mV p-p AVO = –100 40 RL = 10kΩ 0.3 VIN = ±3.5V RL = 2kΩ AV = +1 0.2 30 0.1 INPUT VOLTAGE (V) 2 VOLTAGE (V) 6 –20 TIME (µs) Figure 15.
PAGE 9
Data Sheet AD8675 10k 140 SINK SOURCE PSRR+ PSRR– 120 1k VS – VOUT (mV) PSRR (dB) 100 80 60 100 40 10 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 100M 1 0.001 05564-022 0 10 0.01 0.1 1 LOAD CURRENT (mA) 10 100 05564-010 20 Figure 24. Output Saturation Voltage vs. Output Current Figure 21. Power Supply Rejection Ratio vs. Frequency 148 14.86 147 14.84 146 14.82 145 14.80 VS = ±15V RL = 2kΩ 14.78 143 14.76 142 14.74 141 14.
PAGE 10
AD8675 Data Sheet 0.01 12 VSY = ±15V AV = 1 10 0.001 OUTPUT STEP (V) VS = 5V 0.0001 1k FREQUENCY (Hz) 10k 100k 05564-024 100 Figure 27. Distortion vs. Frequency VIN 6 4 2 VS = 15V 0.00001 10 8 0 0 2 6 4 SETTLING TIME TO 0.01% (µs) Figure 29. Output Step vs. Settling Time to 0.01% VSY = ±15V AV = 1 05564-128 VOUT Figure 28. No Phase Reversal Rev.
PAGE 11
Data Sheet AD8675 TEST CIRCUIT 100kΩ V+ 1 2 7 AD8675 INPUT + 8 3 4 6 OUTPUT VOS TRIM RANGE IS TYPICALLY ±3.5mV V– Figure 30. Optional Offset Nulling Circuit Rev.
PAGE 12
AD8675 Data Sheet OUTLINE DIMENSIONS 5.00 (0.1968) 4.80 (0.1890) 8 4.00 (0.1574) 3.80 (0.1497) 5 1 6.20 (0.2441) 5.80 (0.2284) 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) 0.31 (0.0122) COPLANARITY 0.10 SEATING PLANE 0.50 (0.0196) 0.25 (0.0099) 45° 8° 0° 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.